1. Field of the Invention
The present invention concerns apparatuses to facilitate travel of motor vehicles upon standard gauge rail lines. More particularly, the present invention concerns apparatuses which are adaptable to travel either upon rail lines or upon surface roads. Even more particularly, the present invention concerns an apparatus which can be pulled by a motor vehicle on surface roads, in like manner to a trailer, and can also be deployed upon a railway, with the motor vehicle mounted thereupon and providing the locomotion for the apparatus to travel upon rail lines.
2. Background of the Prior Art
Much of the United States, particularly the areas west of the Mississippi River, were opened for settlement by the building of the railroad lines. In the last 150 years, rail lines have been established that cover virtually every corner of the country. Even with the ascendancy of the automobile and the truck, both pick-up and freight, and the resulting shift in passenger traffic away from the train, the railways remain vital channels for commerce to flow across the nation, and particularly to transport resources, food stuffs and heavy industrial goods.
To maintain these interstate rails, the railroad community regularly inspects and repairs the individual lines and routes. In past days, inspectors either used hand cars or locomotives to slowly traverse the rails. These methods are unsuitable today. Instead, a variety of approaches have been attempted to economically and efficiently transport inspectors and work crews to spots along the rails.
One somewhat recent attempt to address this need is found in U.S. Pat. No. 3,086,483, issued Apr. 23, 1963 to Scheldrup and is entitled "RAIL MOUNTED APPARATUS FOR HIGHWAY VEHICLES". Scheldrup teaches the use of a pair of dual-axle carriages that may be deployed upon the rails, and which are capable of transport thereon. A land-based, two axle motor vehicle is then positioned on the carriages, such that each axle of the vehicle is mounted upon one carriage. The rotation of the drive wheels of the vehicle transmits the force for rotation to the carriage upon which it is mounted to drive the vehicle on the rails.
The preferred modern approach has been to utilize a road vehicle, and especially a truck, that is modified so as to be capable of traversing rail lines via equipment mounted upon the vehicle. One such example can be found in U.S. Pat. No. 3,980,025, issued to Olson. In Olson, rotatable guide wheels are lowered from the body of the truck, normally at the front of the truck. These wheels interact with the track to keep the vehicle on line. The tires of the truck contact the tops of the rails; this is where the traction for vehicular locomotion is supplied.
One drawback in this approach is that the vehicle must be specially made, usually at a significant additional cost. Further, road vehicles such as trucks are not designed for rail travel. Thus, a heavy toll is borne by the vehicle, which deteriorates more rapidly than would otherwise be anticipated. This can affect negatively the safety of the vehicle, including situations where the permanent alteration of the vehicle impairs airbag deployment. Not insignificantly, but logically, warranties issued by the truck manufacturers are usually voided when such modifications are made, and with a resulting decline in vehicle resale value.
Additionally, functionality in many aspects, such as steering, handling and braking, are at times seriously compromised. For example, the wheels in a modified vehicle must be larger. This makes the vehicle taller. Additionally, the distance between wheels on one axle is decreased. These two factors in combination foster a greater likelihood of the vehicle tipping in turns upon surface roads. Also, the turning radius is increased, thus seriously jeopardizing the vehicle maneuverability in evasive or emergency situations.
What is needed is an apparatus to allow motor vehicles to traverse rail lines without incurring the potentially unsafe and permanent modifications currently required. This can be accomplished by providing a carrier which can both ride the rails while supporting the motor vehicle, and also travel upon roadways by towing by the motor vehicle. This allows full use of vehicle and a longer lasting apparatus for rail inspection and/or repair. It is to this continuing need of the railroad industry that the present invention is directed.